/*
系统产生4位随机验证码，验证码可以是数字，大写字母，小写字母的组合。
 */
package com.shuangti;

import java.util.Random;
import java.util.Scanner;

public class Test02 {
    public static void main(String[] args) {
     Random rand = new Random();
     rand.nextInt();
     for (int i = 0; i < 4; i++) {
            int a=rand.nextInt(10-1+1)+1;
            int c=rand.nextInt(90-65+1)+65;
            int d=rand.nextInt(122-97+1)+97;
            int e=rand.nextInt(3-1+1)+1;
            switch (e){
                case 1:
                    System.out.print(a);
                    break;
                    case 2:
                        System.out.print((char)c);
                        break;
                        case 3:
                            System.out.print((char)d);
                            break;
            }

        }








    }

}
